Hello from JustAnswer.
Typically, if someone does not have liver disease, abstinence for 3 weeks is sufficient for the CDT to return to <1.7%. Many people will become normal within 2 weeks, but it takes 3 weeks for better certainty that you will be back to normal.
The issue, of course, is that many people that regularly use alcohol also develop liver disease, and if liver disease is present, that can also affect the CDT. But if you do not have any liver disease, then it would take 2-3 weeks for the test to return to normal.
If I can provide any additional information, please let me know.
If the liver blood tests are normal and the liver is healthy enough to metabolize alcohol normally, then you should be normal within 2-3 weeks.
Please let me know if I can provide any further assistance.